Panspermia and Evolutionary Theory

From: Nicq MacDonald (namacdonald@stthomas.edu)
Date: Sun Dec 17 2000 - 01:42:39 MST


Might the case for extraterrestrial life and the principle of
self-organization have new support?

-Nicq MacDonald

http://www.space.com/searchforlife/aliens_all_001027.html

(From Space.com in cooperation with the SETI Institute)

Are We All Aliens? The New Case for Panspermia

By Robert Roy Britt
Senior Science Writer
posted: 09:00 am ET
30 October 2000

Nestled safely inside the belly of a comet orbiting some unknown star, a
microscopic alien sits dormant. Somewhere in this vast universe -- perhaps a
place like Earth -- a greater destiny awaits the microbe. A place to
flourish, become a nematode or a rose or a teenager.
Life, after all, is tenacious and thrives on change.
Over time, gravity performs a few plausible, but not routine tricks, and the
comet is ejected from its stellar orbit like a rock from a slingshot. For
more than a 100 million years it slips silently across the inky vastness of
interstellar space.
Then gravity goes to work again. Another star tugs at the comet, pulls it
in.
A few giant gaseous planets whiz by, their bulks tugging at the comet,
altering its course slightly. Ahead now, growing larger, looms a gorgeous
blue and brown marble. Water and land. Maybe some air.
Then with the force only the cosmos can summon, the comet slams into the
third rock from a mid-sized, moderately powerful star. The alien microbe
survives, emerges from its protective shell and spreads like the dickens.
Thus began life on Earth, 3.8 billion years ago.
Or so goes one aspect of a theory called panspermia, which holds that the
stuff of life is everywhere and that we humans owe our genesis and evolution
to a continual rain of foreign microbes. It means, simply, that we might all
be aliens.
It's an idea that has been around longer than Christianity, but which still
struggles to gain strong support among most scientists.
But two recent discoveries are breathing new life into the theory.
One study, reported in the October 27 issue of the journal Science, shows
that a space rock could successfully transport life between planets.
Another group of researchers, reporting in the October 19 issue of Nature,
claims to have found and revived bacteria on Earth that were dormant, in the
form of spores, hiding in New Mexican salt crystals for 250 million years.
Scientists called the implications of this second discovery profound,
suggesting that if further study bears out the findings, it could mean
bacterial spores are nearly immortal.
And if you are immortal, then what are a few billion years of interstellar
travel?
"Until recently, panspermia was not even regarded as a scientific
hypothesis," says Chandra Wickramasinghe, the concept's leading proponent.
"Now that has changed."



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